At times threaded members or fasteners (hereinafter referred to as a member or threaded member) become stuck in a work piece or other object. The socket of the member may become rounded or otherwise damaged, for example, such that a standard tool used to tighten and loosen the member can no longer apply enough force to move it. Typical extraction tools and extraction methods to extract a stuck threaded member includes drilling a hole through the centerline of the member and then engaging a tip of the extraction tool in the drilled hole to allow the extraction tool to penetrate and apply force to the stuck member. A typical extraction tool includes multiple left-handed helical splines with long leads to allow generous penetration into the stuck member along the drilled hole. The extraction tool is tapered to help align the tool with the drilled hole. Left-handed splines are used so that when the extraction tool turns counter-clockwise to tighten the tool (to penetrate the tool further into the member, for example) a loosening torque is exerted on the stuck member.
Drilling a hole into the member is not always practical or preferable, however. In the nuclear industry, for example, some containers store highly radioactive material. Due to the radioactivity, handling and operating of these containers is performed remotely using mechanical manipulators located within a shielded hot cell holding the containers. The mechanical manipulators are controlled by operators outside the shielded hot cell. In such operations, a leak seal is often used in conjunction with the extraction tool to prevent radioactive gases from escaping the container. The remote nature of these operations, especially when using a leak seal, makes drilling a hole in the stuck member difficult.
Moreover, existing tools are unable to obtain sufficient penetration for adequately gripping a stuck plug, and require a striking force necessary to “start” extracting a stuck member. Existing tool splines are also easily damaged or sheared during installation or loosening torque application and lack sufficient “grip” within the limited engagement length available to transmit required loosening torque. In view of the foregoing, a need exists for a novel extraction tool and method of extracting a stuck member.